Had Tavares not waited til the last minute to let the Isles know he's leaving - or if the team hadn't decided to be dependent upon his statement as to whether he's staying or leaving - the NYI might have been able to go fishing for a guy like Stastny or Bozak. Theoretically speaking.
But as others here have said, it doesn't look like the Isles want a bonafide #2 center right now, even if a guy like Turris would be available.
The Isles are going in another direction and it's very possible that Lou had already started planning on life without Tavares fairly early after having taken over as the Isles' GM.
It seems to be a sound plan at the moment. If the team competes, he can shore up. If it doesn't, he can move pieces at the deadline. He has a group that's going to be tougher than the average customer and there's good reason to believe that the team will show more character than the past two seasons.
He's brought over Jan Kovar to create competition in camp while, in a best-case scenario, possibly having found a #2 center for the time being.
He's got a Brock Nelson here who is basically the same size and frame as Tavares, but has consistently underachieved while often looking disinterested. Does he bloom under Trotz?
Filppula and Cizikas are fine options for lower lines.
Naturally, there could be problems if several of these guys gets injured or disappoint terribly.
REBUILD:
When you've got Barzal, Lee, Bailey, Eberle, Leddy, and young contributors like Beauvillier, Pulock, and Pelech with a guy like Ho-Sang in the wings and Wahlstrom + Dobson likely ready for impact play in a year's time, you're not really in a rebuild.
Tavares' loss means shifting, no doubt. But it's a difference of culture we're seeing around the organization (would have taken place with Tavares here anyway) and if we're honest, the Isles spent a lot of time in run-of-the-mill no-man's land in recent seasons.
Of course, if a number of the guys who are being invested in fail, then the option is there to move some bodies, make a handful of picks next summer (including a center in the Top 10?), then go after a few big fish on the UFA market.